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Araz kuberin
6,199 Pointspublic Blog(List<BlogPost> posts) { mPosts = posts; }
Hello, what does this do ??
public Blog(List<BlogPost> posts) { mPosts = posts; }
if a constructor then how does it work why we need that ?? since we do not instantiate of the Blog class!
package com.example;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class BlogPost implements Comparable<BlogPost>, Serializable {
private String mAuthor;
private String mTitle;
private String mBody;
private String mCategory;
private Date mCreationDate;
public BlogPost(String author, String title, String body, String category, Date creationDate) {
mAuthor = author;
mTitle = title;
mBody = body;
mCategory = category;
mCreationDate = creationDate;
}
public int compareTo(BlogPost other) {
if (equals(other)) {
return 0;
}
return mCreationDate.compareTo(other.mCreationDate);
}
public String[] getWords() {
return mBody.split("\\s+");
}
public List<String> getExternalLinks() {
List<String> links = new ArrayList<String>();
for (String word : getWords()) {
if (word.startsWith("http")) {
links.add(word);
}
}
return links;
}
public String getAuthor() {
return mAuthor;
}
public String getTitle() {
return mTitle;
}
public String getBody() {
return mBody;
}
public String getCategory() {
return mCategory;
}
public Date getCreationDate() {
return mCreationDate;
}
}
package com.example;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
public class Blog {
List<BlogPost> mPosts;
public Blog(List<BlogPost> posts) {
mPosts = posts;
}
public List<BlogPost> getPosts() {
return mPosts;
}
public Set<String> getAllAuthors() {
Set<String> authors = new TreeSet<>();
for (BlogPost post: mPosts) {
authors.add(post.getAuthor());
}
return authors;
}
}
2 Answers
Joseph Wasden
20,406 PointsIt is indeed a constructor method. remember how a class is like a set of blueprints for an object? Well, when we include a constructor in the class, we allow others to instantiate an object, or in other words construct it, using the constructor method.
without this method, there is no method on the class to call to create the objects described in the class. It would be like having blueprints, but no factory to make the things they describe.
Araz kuberin
6,199 PointsOK i got it thx!